1. Field of the Invention
This invention relates to providing an unobstructed passageway through a sliding door and additionally to providing a barrier to prevent water infiltration through the door opening.
2. Summary of the Background Art
In many areas prone to high velocity winds and rain, a watertight barrier is provided to prevent water intrusion into a building. For example, the threshold frame member forming the lower portion of the frame structure extending around a sliding door is provided inside the door with a leg extending upward from the floor to a height required to accommodate a particular water level or design pressure. The problem with this approach is that the barrier presents a tripping hazard to people walking through the open doorway, and a serious obstacle to anyone trying to roll a wheelchair or wheeled cart through the door opening. There are numerous instances of conflict between building codes requiring such barriers to prevent damages from water penetration and federal regulations covering ADA (Americans with Disabilities Act) Standards for Accessible design.
In some locations, these problems can be alleviated by building ramps extending downward from the top of the obstruction to the surfaces inside and outside the building. However, when such ramps are built at the degree of slope mandated for wheelchair usage, they are often too long to be used with narrow walkways, balconies or patios outside or with small rooms inside. Therefore, what is needed is a mechanism for sealing against water intrusion that moves out of the way, as a sliding door is opened.
Sliding doors of vehicles, such as vans, and of many railroad freight cars, are provided with airtight sealing mechanisms that are additionally watertight at least under rain conditions, with the door being mounted on cranks that allow it to move inward into the mating opening and outward therefrom. The sealing process occurs as the door is moved inward, and the seals are broken as the door is moved outward. While the door is held outward by the cranks, it is slid along the outside of the wall of the vehicle or railroad car. What is needed is a way for providing a watertight opening at a sliding door within a building where weather conditions include high winds and rain, without requiring a different type of door movement and without significantly changing the appearance of the building when the door is open.
U.S. Pat. No. 5,870,859 describes a watertight sliding door structure including a movable door, a stationary door, which is made watertight without increasing the height of a portion of the sill. The movable door and the stationary door are each provided with a stile extending vertically along the central edge of the door. As the movable door is closed, these stiles meet one another, with the gap between them being sealed by elastomeric strips. Horizontally extending sealing strips are also provided along the upper and lower frame members of the doors. A pressure-equalized clearance area is formed between the sill of the window frame of the movable door and the stationary door and attachments provided on the sill. Additionally, an airtight member is provided to divide the pressure-equalized clearance area into and an inside clearance area of the single movable door. By forming the pressure-equalized clearance area between the inside clearance area and the outside clearance area of the single movable door in the sill partition, a difference in the pressure between the sill portion and the outside is not produced, so that rain water is exhausted by a dead load. What is needed is a method for sealing a sliding door assembly without requiring that a movable door to be slid open and shut with elongated sealing members in sliding contact with opposing surfaces.
Japanese Patent Application 11182154A describes a water barrier plate that moves vertically with the movement of a flexible door extending around the walls of a stall within a bathroom. The door is opened by moving the flexible door so that a space between its opposite ends is aligned with an opening in the walls, with pins at these opposite ends moving the water barrier plate downward into a slot within the threshold as the door is fully opened. The door is closed by moving the flexible door so that the space between these opposite ends is aligned within the walls, with these pins moving the water barrier plate upward within the slot. What is needed is a water barrier that can be moved out of the way without causing the barrier to retract into a slot extending downward within the floor, so that there is no need to weaken the floor structure with such a slot, and so that the apparatus can be readily installed in an existing building. Additionally, what is needed is an apparatus operable with a conventional sliding door, in which the entire door moves to one side of a passageway as it is opened.
U.S. Pat. Nos. 4,692,961 and 5,560,164 describe water-shielding structures for removable placement in openings of buildings. What is needed is a structure that can be left attached within a doorway without impeding traffic through the passageway.
A number of patents, such as U.S. Pat. No. 4,237,664, describe door sill structures including surfaces of different elevations to prevent water intrusion without addressing the difficulties in access by foot or wheelchair that may be caused by such changes in elevation.